As a conventional technique in the above-described technical field, for example, a radiation detection element described in Patent Document 1 has been known. The radiation detection element described in Patent Document 1 includes a glass substrate, an optical sensor unit including a plurality of photoelectric conversion elements which is provided on the glass substrate, a planarizing film provided on the optical sensor unit, and a plurality of scintillator sections which are provided on the planarizing film. In particular, in this radiation detection element, a plurality of convex portions corresponding to the respective photoelectric conversion elements are formed on the planarizing film, and the respective scintillator sections are formed on the upper surfaces of the convex portions so as to be partitioned while being in contact with each other.